Packing ring



M. R. BUFFINGTON PACKING RING Filed April 9, 1935 Feb. 2, 1937.

INVENT OR i Wwf@ 12a/mw A TTORIVEYY Patented' Feb. 2, 1937 UNITED STATES PATENT OFFICE 11 Claims.`

This invention relates to oil cups for use in connection with hydraulic pumps and more particularly to cupped plunger packing rings particularly adapted for use in connection with oil well pumps.

The oil cups or plunger packing rings which are in use at the present time are generally molded from a leather composition, but are also formed having alternate layers of duck fabric and hard rubber.

One diiculty encountered in connection with these oil cups now in use is that sand at the bottorn of the well being pumped cuts and rapidly wears the surface of the cups. In operation, a i5 canvas or duck fabric cup generally lasts about one week when used in connection with oil wells which are pumped every other day. Oil cups which are made from leather are also easily cut by sand or grit at the bottom of the working barrel and it frequently occurs that portions of the cup body are torn off so that it becomes necessary to halt the pumping operation in order to remove the separated parts of the cup to prevent clogging of the pump.

Oil cups have also been made from vulcanized rubber, but such cups vary greatly in flexibility and in the property of swelling in contact with mineral oil. The variation in the swelling property depends upon the degree of vulcanization of the rubber composition by which the hardness of the cup may be controlled. It has been found, however, that oil cups which are not completely vulcanized do not have the requisite strength and have too great a swelling action in contact with oil, although they do have the flexibility which is desired in order to obtain sealing action in the working tube.

It will be understood that in operation, the oil cups expand against the working barrel to a greater or less extent depending upon the working pressure to which it is subjected. In connection, with the use of ordinary vulcanized rubber, however, the cups have little flexibility if the rubber is fully vulcanized to the degree in which the rubber is unaffected by contact with the oil, lIn connection with the use of ordinary rubber no intermediate degree of vulcanization has been found in which the cup has a sufficient degree of flexibility, together with the property of resisting the solvent action of the oil, together with a suflicient degree of toughness to withstand the abrasive action of the sand encountered under working conditions. It has been found furthermore that by vulcanizing the rubber only to the degree in which flexibilityV is retained, the

cup has insulcient strength and will flop when it is withdrawn from the Working barrel, so that replacement becomes necessary.

I have discovered that bythe use of synthetic rubber in place of ordinary rubber in the making of oil cups, the life of the cup and the flexibility and sealing action under ordinary working conditions is very greatly improved. In the practice of my invention I preferably employ the polymer of chloro-prene which may be com- 30 pounded and vulcanized in substantially the same manner as ordinary rubber. The molded product obtained by the use of synthetic rubber is greatly superior, however, for use in connection with mineral oil, for the reason that while the cup 15 has a marked flexibility which permits it to seal properly in the working barrel, it is substantially unaffected by prolonged contact with mineral oil and does not have the tendency to swell as is the case when ordinary rubber is used. Furthermore, the surface of the cup is of such a nature that when it contacts with sand it is not cut and the sand merely rolls on the surface without tearing the cup or producing substantial wear.

The form of synthetic rubber-which I have found best adapted is the material known as Duprene, which may be purchased on the market. Another form of synthetic rubber which may be used is that which is sold on the market under the name of Thiokol, this material being a reaction product of ethylene dichloride and sodium sulde. It has been found that by the use of these synthetic rubber compositions the oil cup made therefrom retains its tensile strength over a long period of time and the life of the cup is thereby increased many fold over that of the ordinary rubber oil cup.

The use Vof this material in the making of oil cups of my construction is of particular advantage in that the same molding time and molding temperature may be employed in the making of the oil cup irrespective of the particular uid pressure in the well in which it is to be used and the flexibility and other physical characteristics of the cup may be controlled by modifying the dimensions of the cup and its reenforcing element as will be hereinafter described.

One of the features of my invention which permits expansion. of the lip of the `oil cup into o contact with the working barrel to form a seal, but at the same time prevents opping of the valve, is the use of a reenforcing member having a flange portion at the upper part thereof which serves to reenforce the lip portion or contacting portion of the cup, thereby increasing its strength and its resistance to opping".

Another feature of my invention is the use of an insert or liner in the oil cup' serving to convert it to a substantially solid plunger without interference with the flexibility or expansibillty of the lip portion which during operation expands into contact with the working surface in the well tubing. The liner is preferably made of the same material as that of the body of the cup and serves as a reenforcing element, taking the place of the follower ring above the lowermost oil c up on thepiston. e

One object of the present invention is to provide a form of construction and composition which may he employed under substantially all conditions encountered in the pumping of oil wells.

Another object'of the invention is to provide a suitable composition which may be molded in a uniform time and at a uniform temperature to form a product having suitable characteristics irrespective of the iiuid pressure to which the cup is to be exposed and by means of which the proper sealing action in the well tubing may be obtained. Y

Another object of the invention is to provide a novel form of cup in which the resistance to flopping is increased to such an extent that under ordinary conditions of use, floppng or tearing of the cup body is entirely prevented.

Another object of the invention is to provide a form of cup which is adapted for continuous use and the life of which is greatly increased.

With these and other objects in view the invention comprises various features hereinafter more fully described and particularly defined in the claims.

'I'he various features of the invention are illustrated in connection with the annexed drawing in which:

Fig. 1 is a cross sectional view of an oil cup embodying the preferred form of the invention;

Fig. 2 is a view in perspective of the reenforcing member, showing the preferred form of construction; p

Fig. 3 is a view in elevation of a well tubing showing the ordinary form of piston or plunger therein to which the oil cups are attached, the cups being held in place by means of a follower ring as shown;v

4 is a view in elevation of a modified form of the reenforcing element in the cup;

Fig. 5, is a plan view of a form of metal insert or reenforcing member in which the walls are iiuted; and

Fig. 6 is a view of the form of oil cup shown in Fig. 1 together with an insert or liner.

Referring more in detail to the drawing, the numeral 2 designates the body of the oil cup in which is embedded a reenforcing member 4. The composition of the body of the oil cup is preferably a synthetic rubber composition such as the polymer of chloro-prene which is treated with vulcanizing ingredients to form a moldable plastic composition.

The reenforcing element 4 is preferably of y metal and is provided with a series of openings 6 formed at about the middle of the reenforcing member. 'I'hese openings permit the synthetic rubber composition to flow through the openings l during the molding operation, serving to unite the body portions of the composition on both sides of the reenforcing member. At the top portion of the reenforcing member is preferablyggvided a flange or lip member 8 which exten outwardly arid downwardly from the upper edge of the member and is preferably of a width equal to about one half or three fourths of the thickness of the\ad'iacent portion of the oil cup body. This construction permits the lip member I0 of the oil cup to expand under the internal pressure to insure sealingor wiping action during pumping.

The flexibility and resistance of the oil cup to opping may readily be varied to adapt it to particular conditions of use by suitably varying the thickness of the lreenforcing element and modifyingits proportions to obtain the desired characteristics. The vgdth of the lip portion may be varied to some ext nt and the height of the body portion of the reenforcing element may be varied so as to provide a greater or less degree of strength and flexibility as may be desired.

The lower portion of the reenforcing member is preferably provided with an inwardly projecting ange member I2 which serves to reenforce the lower part of the oil cup and to give the desired degree of rigidity to the portion of the cup in contact with the body of the piston. y

A form of reenforcing member similar to that shown in Figs. 1 and 2 but in which a ridge portion or zigzag portion is formed near the middle of the body portion is illustrated in Fig. 4 of the drawing. This form of the reenforcing .member is particularly desirable where a greater than the ordinary thickness is to be used in the body of the cup member and in' which greater exibility is desired. 'I'he reenforcing member may be provided with two series of openings 6 and I4, which are similar to the openings 6 used in the preferred form of the invention, which serves to increase the resistance to tearing and to increase the flexibility of the cup.

Another modification which may be employed is illustrated in Fig. 5 of the drawing in which the body portion of the reenforcing element 'may beiiuted to give a greater degree of expansibility or lateral exibility. In this form of the ldevice the reenforcing element is preferably further modified in that the upper lip portion is omitted, although Va separate flange or lip member may be used .if desired over the top of the uted member s o as to reenforce the lip -member 20 is preferably made of the same material as the cup wearing surface, being of synthetic rubber, as above disclosed in connection with the composition of the body 'portion of the cup member.

The liner member fits within the cup member so that the lip member I0 engages a parallel surface on the underside of the lip portion 26 of the liner. The inner edges 24 and 28 and the inner surface 22 of the liner are of a diameter so as to fit vover the body portion of the piston member.

Illhe method of use of the oil cup and the liner or insert member will be obvious to those skilled the operation of the plunger.

in the art. 'Ihe piston 3 is operated in the Well tubing ,5 by a rod 40 in the usual manner, the body portion of the piston being hollow, as indicated in the dotted line portion 9, and having an upper trapping valve or ball valve member 1 which serves to permit upward flow of oil through the ports 38 during the downward movement of the piston and prevents iiow through the hollow portion of the piston during the upward movement of the `piston when the ball 31 of the standing valve 36 is open. The lowermost cup member 2 is preferably held in place by means of a metal follower ring 30 screwed onto the body portion of the piston member. Above the lowermost oil cup and below the uppermost oil cup, as between the lower cup member andthe next adjacent cup member, for example, I preferably employ the liner member 20 as above described which gives a greater degree of flexibility: in At the lower end of the plunger is a jam nut 3l having ports 34 therein which permit oil to enter the interior passage of the plunger on the downward movement of the plunger, during which the ball ofv the standing valve 36 is closed.

In constructing an oil cup or packing ring by my method, a metal shell of brass or other suitable material is preferably spun or stamped from the metal so as to have a slightly larger diameter than the desired inside diameter or dimension of the cup. The shell or reenforcing member 4 is preferably drilled at spaced intervals so as to provide the openings or holes 6 through which the material of the cup projects to form the integral structure in which the metal unit serves as a reenforcement. After the metal shell or reenforcing member is,suitably constructed. it is suitably placed in a mold and the heat curing plastic material or synthetic rubber material with the vulcanizing ingredients therein is vthen forced into the mold Yaround the shell nr reenforcing element to provide a layer of plastic material on each side of the shell, these layers being united by the parts of the composition which project into the openings forming pins or rods which assist in forming an integral structure after the molding operation.

After the cup material has been suitably placed in the mold it is subjected to the usual vulcanizing temperature so as to completely vulcanize the material in the body portion of the cup.

As abo-ve described, it has been found that the strength and other properties which affect sealing action of the cup against the walls in the working portion of the tube may be varied by modifying the physical characteristics of the cup without modifying the chemical properties of the synthetic rubber composition used in the body portion of the cup. The composition as above described is suitable for both high and low pressures when provided with a suitable reenforcing element which expands at the proper pressure.

Itis to be particularly noted in connection with the Vdrawing showing the preferred construction that the shell vor reenforcing member is preferably embedded so that the upper lip or flange portion is below the top of the inner wall of the cup. The material of the body portion of the cup member obviously expands more than the metal shell or reenforcing member at a given pressure and the lip member serves to provide a flexing action at the top of the cup to permit the lip portion to maintain sealing action with the side walls of the tubing during the lifting stroke. This construction also prevents fiopping of the cup when it is withdrawn out of contact with the side walls of the well tubing.

It will be understood that the liner or insert member 2D as shown in Fig. 6 of thejdrawing may be manufactured in substantially the same way as the oil cup member by molding a synthetic rubber composition having suitable vulcanizing ingredients therein to obtain the desired physical characteristics. It will be understood also that while the insert member is preferably made of a synthetic rubber composition such as Duprene, the construction may be modified to -some extent by the use of fabric at the interior'portion thereof, although it is to be understood that the working surfaces are to be entirely of the synthetic rubber composition in order toA withstandthe solvent action of the oils with which it is in contact and to obtain the desired resistance to wear when in contact with sand, grit or such materials as cause deterioration and rapid wear of ordinary rubber.

Having thus described the invention, what is claimed as new is:

1. A packing ring comprising a substantially circular body portion composed of vulcanized synthetic rubber composition, said body portion having a centrally disposed opening, an outwardly extending lip portion at the upper part of said packing ring, an inwardly extending base portion at the lower end of said packing ring, a reenforcing member within said body portion wardly extending projection thereon adjacent the said lip portion to reenforce said lip portion 1 and to prevent iiopping of the cup member and an inwardly projecting flange part for reenforcing the said base portion of the packing ring.

2. A packing ring comprising a substantially circular body portion composed of a molded vulcanized synthetic' rubber composition, said body portion having a centrally disposed opening, an outwardly extending lip portion at the upper part of said packing ring, an inwardly extending base portion at the lower end of said packing ring, a metallic reenforcing member within said body portion having an upper outwardly extending flanged part having a downwardly extending projection at the outer edge thereof adjacent the said lip portion to reenforce said lip portion and to prevent fiopping of the cup member and an inwardly projecting flange part for reenforcing the said base portion of the packing ring.

3. A packing ring comprising a substantially circular body portion composed of a vulcanized syntheticv rubber composition derived from chloro-prene. said body portion having a centrally disposed opening, an outwardly extending lip portion at the upper part of said packing ring, an inwardly extending base portion at the lower end of said packing ring, a metallic reenforcing member within said body portion having an upper outwardly extending flanged part having a. downwardly extending projectionthereon adjacent the said lip portion to reenforce said lip portion and to prevent opping of the cup member, a midportion having means for rendering the body portion flexible and for anchoring the said composition to the said reenforcing member, and an inwardly projecting flange part at the lower portion of the reenforcing member for reenforcing the said base portion of the packing ring.

Cil

-member having a substantially cylindrical main portion, an upper outwardly extending iianged portion for reenforcing said lip portion, and an inwardly extending flanged portion extending within the said inwardly extending base portion for reenforcing the same.

5. A packing ring comprising a substantially circular body portion composed of a rubber composition, said body portion having a centrally disposed opening, a lip portion at the upper part thereof,A an inwardly extending base portion at the lower part thereof, a reenforcing unitary me-v tallic member embedded within said body portion, said member having a substantially cylindrical main portion, an upper outwardly extending flanged portion having a continuous solid periphery for reenforcing said lip portion, and an inwardly extending flanged portion having a Icontinuous solid periphery extending within the said `inwardly extending base portion for reenforcing the same.

6. .A packing ring comprising a substantially circular body portion composed of a synthetic rubber composition,said body portion having a centrally disposed opening, a lip portion at the upper part thereof, an inwardly extendingbase portion at the lower part thereof, a reenforcing member embedded within said body portion, said member having continuous solid peripheral portions to prevent undue bending thereof and having a substantially cylindrical main portion, an upper loutwardly extending flanged portion for reenforcing said lip portion and an inwardly extending flanged portion extending within the said inwardly extending base portion for reenforcing the same.

7. A packing ring comprising a substantially circular body portion composed of a synthetic rubber composition, said body portion having a centrally disposed opening, an upwardly extending lip portion at the upper part thereof, an inwardly extending base portion at the lower part thereof, a metallic reenforcing member embedded within said body portion, said member having continuous solid peripheral' portions to prevent portions thereof from bending and openings within the marginal areas through which the body portions on both sides of the said reenforcing member are united, said member having a substantially cylindrical main portion, an upper outwardly extending flanged portion for reenforcing said lip portion, and an inwardly extending flanged portion extending within the said inwardly extending base portion for reenforcing the same.

8. A packing 'ring comprising a substantially circular body portion composed of Duprene,

the said ariged portions having continuous solid peripheral areas serving tostrengthen the said lip portion and said base portion.

9. A packing ring comprising a tubular body portion composed 'essentially of vulcanized Duprene, a lip portion at the upper part of said body portion adapted to provide an initial seal when subjected to oil under pressure and a substantially solid reinforcing member embedded inv said body portion, said reinforcing member extending adjacent to but short of the said lip portion whereby to retain the shape of the body portion during swelling thereof toward body sealing position `when subjected to the oil and yet protect the lip against excessive strain during said initial sealing action.

10. A packing ring comprising a tubular body portion composed essentially of vulcanized Duprene, said body portion having a centrally disposed opening, a lip portion at the upper part of said body portion adapted to provide an initial seal when subjected to oil under pressure, an inwardly extending base member at the lower extremity of said body portion and a substantially solid reinforcing member embedded in said body portion, said reinforcing member extending adjacent to but short of the said lip portion whereby to retain the shape of the body portion during swelling thereof toward body sealing position when subjected to the oil, and yet protect the lip against excessive strain during said initial sealing action.

11. A packing ring comprising a tubular body portion composed essentially of vulcanized Duprene, said body portion having a centrally disposed opening, a lip portion at the upper part of said body portion adapted to provide an initial seal when subjected to oil under pressure, an inwardly extending base member at the lower extremity of said body portion and a substantially solid unitary metal reinforcing member completely embedded in said body portion, said reinforcing member having a substantially tubular main portion, an inwardly extending flange portion extending into and reinforcing said base member and a top portion extending adjacent to but short of the said lip portion whereby to retain the shape of the body portion during swelling thereof toward body sealing position when subjected to the oil and yet protect the lip against excessive strain during said initial sealing action.

MALCOLM R. BU'FFINGTON. 

